1. Field of the Invention
This invention pertains to fiber optic attenuators. More particularly, this invention pertains to an attenuator which may be continuously varied to have an attenuation throughout a range of values.
2. Description of the Prior Art
In the prior art, optical attenuators are provided to attenuate a light signal passing through optical fibers. Examples of optical attenuators are shown in U.S. Pat. Nos. 4,557,556 and 4,557,557 as well as U.S. Pat. No. 4,893,889.
Variable attenuators are also known. An example of such is shown in U.S. Pat. No. 4,904,044. That patent teaches a continuously variable fiber optic attenuator which utilizes a flexible filter of varying optical density.
It is an object of the present invention to provide a variable attenuator for a fiber optic transmission system. It is a further object of the present invention to provide such an attenuator which is of low cost manufacture. A still further object of the present invention is to provide a variable attenuator which is variable over a wide range of attenuation values.